This suggestion follows from a thread on forum.qt.io.
When configuring the "Deploy to Remote Linux Host" run settings in a Makefile/Generic project, the "Files to deploy" table is always empty regardless of the QtCreatorDeployment.txt contents. That file seems to only be used in CMake-based projects, QtCreatorDeployment.txt support should be available in Makefile/Generic projects.
The same issue was discussed in
QTCREATORBUG-12168, but the resolution (setup scp manually as a deployment step) differs from other project types, and so is unsatisfactory.
Of course it would be better if we could do away with QtCreatorDeployment.txt altogether and just be able to manually add entries to the "Files to deploy" table - but that's a different moan...